Oil/water interfaces of guar gum-based biopolymer hydrogels and application to their separation

Oily wastewater treatment has become a significant research subject due to potential environmental related applications, e.g., oil spill remedy process. In this paper, a natural polymer based hydrogel, prepared from guar gum (GG) and metaborate, was coated onto a stainless steel mesh, and the as-prepared hydrogel-coated material was applied for oil/water separation. The strong hydrophilic GG hydrogel imparted excellent underwater oleophobicity and ultra-low oil adhesion. The results proved that the as-prepared GG hydrogel-coated material possessed excellent self-cleaning property and high oil/water separation efficiency.